Solid ink or phase change ink printers conventionally receive ink in a solid form, either as pellets or as ink sticks. The solid ink pellets or ink sticks are typically inserted through an insertion opening of an ink loader for the printer, and the ink sticks are pushed or slid along the feed channel by a feed mechanism and/or gravity toward a heater plate in the heater assembly. The heater plate melts the solid ink impinging on the plate into a liquid that is delivered to a print head for jetting onto a recording medium.
The correct loading and feeding of ink sticks has typically been accomplished by incorporating loading features, such as, for example, keying, guiding, alignment, orientation and/or sensor actuating features, into the exterior surface of an ink stick. The loading features may comprise protrusions and/or indentations that are located in different positions on an ink stick for interacting with key elements, guides, supports, sensors, etc. located in complementary positions in the ink loader. In addition, loading features may include ink stick shapes and/or features that aid a user in visually identifying the ink stick or correctly orienting the ink stick for insertion. For instance, ink sticks may include a surface that has been marked with a visually recognizable symbol such as color slot identifier, logo, or shop keeping unit (SKU) designation.
The loading features of ink sticks have typically been focused on multiple axis interfaces with the ink loader: at least one axis corresponding to insertion and at least one other axis corresponding to feed, with the former axis typically transverse to the latter. For instance, keying and orientation features of an ink stick may be oriented along an insertion axis while support/guidance and sensor features may be oriented along a feed axis.
The manufacturing of ink sticks having multi-axis loading features may be limited by fabrication technology. For instance, previous ink sticks have been manufactured with a formed tub and flow fill process. In this method, the ink stick composition is heated to a liquid state and poured into a tub having an interior shape corresponding to the desired finished ink stick shape. Shapes and features created in this fashion, however, are generally restricted to the bottom and side surfaces of the ink stick. Compression or injection molding may expand the manufacturing capability to allow the formation of ink sticks of nearly unlimited shapes with features on all surfaces. The tooling for such ink sticks, however, may become prohibitively expensive, and the resulting ink sticks may be difficult to remove from the tooling. Benefits to more complex ink shape opportunities exist and can be encouraged as solutions to these manufacturing problems are addressed.